1. Field of the Invention
This invention relates to a dispensing package for administering a medical preparation to a human nasal cavity. More specifically, the invention relates to a package having flexible walls and an upwardly directed dispensing orifice preceded by a swirl chamber operating in the absence of air and adapted in dispensing the preparation to break it up into a fountain of relatively large droplets, as opposed, for instance, to an aerosol spray.
2. Description of Related Art including Information Disclosed under .sctn..sctn.1.97 to 1.99
The prior art is replete with dispensing packages of the squeeze bottle type adapted to deliver liquid in spray form. An example is shown in the U.S. Pat. No. 3,519,208 which issued July 7, 1970 to P. A. Marchant wherein the squeeze bottle is provided with a plug having a dip tube extending down into the liquid. A space is provided in the plug to permit air from above the liquid to blend in with the liquid as the liquid dispenses in spray form. Other examples of such dispensers wherein air is blended along with the dispensing liquid are U.S. Pat. No. 2,642,313 issued June 14, 1949; U.S. Pat. No. 2,658,797 issued Nov. 10, 1953; U.S. Pat. No. 4,020,979 issued May 3, 1977.
The prior art also includes flexible-walled containers having inner rupturable capsules so that just prior to use the inner capsule can be ruptured by squeezing the outer container allowing the materials in the inner capsule and the outer container to contact, react or dissolve immediately prior to use. Examples are shown in U.S. Pat. No. 2,687,130 issued Aug. 24, 1954 and U.S. Pat. No. 4,540,089 issued Sept. 10, 1985.
The benefits of administration of medical preparations by way of the soft tissue in the nasal cavity have been recognized recently. More specifically, the administration of an aspirin solution, for instance, through the nose to engage on the soft tissue in the cavity has been found to be almost as fast acting as an intravenous injection; much more rapid in effect than oral administration.
The importance of speed in getting aspirin actually into the bloodstream in the treatment of migraine headaches, for instance, has been indicated by clinical studies:
If taken in the early stages of an attack, aspirin may be of benefit by impairing platelet aggregation. This aggregation precedes serotonin release from platelets, an event which may be of considerable importance for the migraine attack. At a later stage in attacks, aspirin, or the salicylate derived from it, may inhibit prostaglandin synthesis, and thus help relieve pain. There is some evidence that aspirin intake early in the course of migraine attacks is associated with better pain relief than when aspirin is taken later in attacks. FNT The above quotation if from an article in Cephalalgia(1982:2:71-76) entitled "Aspirin Treatment of Migrain Attacks: Clinical Observations" by Ross-Lee L, Eadie M. J., Tyrer J. H.
There is, therefore, a need to provide a personal ready-to-use package, preferably suitable for carrying in a woman's handbag or a man's pants pocket, by which medicine such as aspirin can be delivered by the patient himself into the nasal cavity. This would enable the user to administer the medicine to himself the moment he detected the need, as for instance, the onset of a migraine attack. Preferably such a package can can take the form of a squeeze bottle similar to the nasal anti-inflamatory products widely on the market.
Nasal squeeze bottles now marketed however and, as noted above, have spray-producing nozzles which would not be optimum for the present purpose. Invariably they lead the liquid up to a mixing chamber in which the liquid is blended with air from the bottle above the liquid level. The air breaks up the liquid into fine particles, some of which are so fine that they are inhaled into the lungs and do not remain in the nasal area. For purposes of a respiratory anti-inflamatory or epinephrine this more general application is appropriate.
However, in the present instance more precise delivery to a local area in the nasal cavity is the objective for at least two reasons. First, the dosage of medicines that are to be absorbed into the bloodstream can best be controlled if it is all delivered to the area, namely the permeable tissues in the roof of the nasal cavity which readily absorb the medicine. There is the related drawback of a mist-type spray that in this use delivery of the proper dosage to the desired local area would require many times the necessary number of squeezes, with the majority being diffused over an area in which it would not be effective at all (windpipe, lungs, etc). This would be needlessly burdensome and time-consuming to the user.
Second, some medicines, for instance aspirin, have acid or a basic character which would needlessly irritate the respiratory tissues.
There is need, therefore, to provide in such a medicine dispensing package a nozzle which produces a fountain of large droplets which impact on and remain for the most part on the roof tissues of the nasal cavity, but are large enough so that they do not become entrained in the airstream of the inhaling subjects as do the fine mist-type sprays of the prior art.